feat: add goatcounter integration

To enable the goatcounter integration, the variable
VITE_QUEER_LEXIKON_PRIVATE must be set to "true". This check is
intentionally added for development environments so that all dev
environments from possible forks do not modify the statistics by
accident.

.env

@@ -0,0 +1,2 @@
+VITE_QUEER_LEXIKON_PRIVATE=false
+

main.ts

@@ -5,6 +5,7 @@ import { initializeMap } from "./ts/map";
 import "@fontsource/ubuntu/latin.css";
 import { setupLegend } from "./ts/legend";
 import { setupEmergencyButton } from "./ts/emergency-button";
+import { addGoatCounter } from "./ts/goatcounter";
 
 document.addEventListener("DOMContentLoaded", () => {
 	initializeMap();
@@ -12,4 +13,8 @@ document.addEventListener("DOMContentLoaded", () => {
 	setupHamburger();
 	setupLegend();
 	setupEmergencyButton();
+
+	if (import.meta.env.VITE_QUEER_LEXIKON_PRIVATE === "true") {
+		addGoatCounter();
+	}
 });

ts/env.d.ts

@@ -0,0 +1,12 @@
+interface ImportMeta {
+	readonly env: ImportMetaEnv;
+}
+interface ImportMetaEnv {
+	// This variable is set in our GitHub Actions for adding additional features
+	// that should be only available on karte.queer-lexikon.net and not
+	// for development purposes.
+	//
+	// Although it's actually a boolean, all environment variables are strings, so we
+	// type it as string here as well.
+	readonly VITE_QUEER_LEXIKON_PRIVATE?: string;
+}

ts/goatcounter.ts

@@ -0,0 +1,22 @@
+declare global {
+	interface Window {
+		goatcounter: {
+			path: (p: any) => string;
+		};
+	}
+}
+
+export const addGoatCounter = () => {
+	window.goatcounter = {
+		path: function (p: any) {
+			return location.host + p;
+		},
+	};
+
+	let goatcounter = document.createElement("script");
+	goatcounter.src = "//ziege.queer-lexikon.net/count.js";
+	goatcounter.async = true;
+	goatcounter.setAttribute("data-goatcounter", "https://ziege.queer-lexikon.net/count");
+
+	document.head.appendChild(goatcounter);
+};

tsconfig.json

@@ -1,7 +1,7 @@
 {
 	"exclude": ["/dist"],
 	"compilerOptions": {
-		"module": "ES2015",
+		"module": "ES2020",
 		"strict": true,
 		"lib": ["DOM", "ES2015"],
 		"target": "ES2015",